Rotahy pumf



Aug. 28, 1928.

' E. B. 'I 'Arr ROTARY Pura? Filed Nov. 26, 1926 2 Sheets-Sheet 1 "Orl 4 Aug. 28, 1928.

E. B. TAlT ROTARY PUMP Filed No?. 26, 1926 2 Sheets-Sheet 2 Armi/vir dil Patented Aug. 28, 1928.

UNITED STATES 1,682,258- gPATENT oFFlcEg..

EDWARD BERRY TAI'I, OF COLCHESTER, ENGLAND.

ROTARY PUMP.

Application led November 26, 1926, Serial No. 150,961, and in Great Britain December 15, 1925.

This invention relates to rotary pumps of the screw or worm type, and it has for its object to improve the eiiciency of this type .0f pumpand to make it more convenient to handle and run. v

According to my invention the screw or worm of the pump hereinafter called the rotor consists of a body of conical form having a screw thread on its coned exterior surface, the relative sizes and shapes of said rotor and of the pump chamber in which said rotor revolves being suitably proportioned and arranged according to the duty the pump is designed to perform. At the smaller end of the pump is an inlet chamber and at the larger end of said pump chamber is a discharge chamber which is of a voluter or other suitable form and is provided with a suitable outlet. The inlet branch is raised to any desired height relative to the inlet chamber in order to ensure a certain amount of water remaining in the pump when it is stopped irrespectiveof whether the suction pipe is fitted with a non-return valve or not or whether the level of the water `from which the pump is drawing relative to the position of the pump. To ensure this by preventing the water in the pump from siphoning out an air connection is made between the upper part of the inlet chamber and the highest part of the inlet branch so that when the pump is stopped any siphon action in theinlet or suction pipe which would operate to draw all the water out of the pump is automatically destroyed when the water level in the pump falls below the opening of said air connection into the inlet `chamber which ensures that the pump wiil remain charged with water and so be ready to function again even Vif the suction pipe is empty.

1n order to seal the fine clearance between the tip of the thread on the rotor and the pump chamber when starting the pump and while the air inthe inlet and suction pipe is being exhausted a suitable connection is provided between the discharge outlet below the level of the water therein when the pump is stoppedand the suction inlet which permits of water flowing from the discharge outlet into the suction inlet which entering the revolving rotor is thrown by centrifugal A force to the tip of the worm thread and thus operates to seal the clearance space between said tip and the face of the pump chamber. In the accompanying drawing Figure i. is

a view in end elevation of the preferred form of my invention. Flgure 2 is a view 1n longitudinal sectional elevation thereof, and

Figure 3 is a View in plan thereof.

Throughout the views similar parts are marked with like numerals of reference.

The pump chamber 1 is cone-shaped and Within it is mounted a cone-shaped rotor 2 Whch comprises a body with an external screw thread also of conical form` The chamber 1 is mounted on a suitable foundation 3 andthe rotor 2 is mounted on a shaft- 4 which runs in suitable bearings 5 and stuifing boxes 6 inthe casing of the pump, a thrust bearing 7 being provided at that end of the pump casing adjacent to the smaller end of the pump chamber to take up the end thrust of said shaft. y

To enable the rotor 2 to be set up to reduce the clearance between the tip of its screw thread and the face of the pump chamber 1, means such as thev set screws 8 are provided for the purpose of adjusting the position of the thrust bearing 7 relating to the casing of the pump.

rlFhe smaller end of the pump chamber 1 opens into an inletu or suction chamber 9 into which the inlet branch 10 leads. This inlet pipe is 'carried to such a height above the 'chamber 1 as will ensure a certain amount of water remainin in the pump when same is stopped if no cot valve is iitted to the into a volute discharging chamber 11 having a delivery outlet i2 which is adapted to receive the discharging pipe.,

To prevent the water retained in the pump when the pump is stopped from being siphoned out by the back dow in the suction. pipe a pipe 13 is run from the highest point of the inlet branchl() to a point lain the upper part of the suction chamber 9.

When starting u under the above conditions, the rotor wliien revolving draws the 'contained water in the suction chamber' and inlet branch and discharges it, together with the water contained in the' annular space between the body of the rotor and the pump chamber, into the discharging chamber and thus to the delivery outlet. This water'is'4 prevented from flowing back by the continued rotation of the rotor which then exhausts the air from the inlet branch and suction pipe thus creating a vacuum which causes the water to rise in the suction pipe and .lill the pump.

In order to seal the fine clearance between the tip of the screw thread of the rotor and the pump chamber when starting and during the discharge of the air in the suction pipe a pipe 15 is run from a point 16 in the discharge outlet below the level of the water therein when the pump is" stopped to any convenient point at the suction end of the ump such for instance as thepoint 17 in tlih inlet branch 10, a stop cock 18 being provided to open and close this passage.

The bearings 5 may be water cooled as shown in Figure 2, to which end said bearings are connected by pipes 19 and 20 withy the discharge outlet 12.

What l claim is 1. The combination in a rotary pump of the screw type, oi a lcone-shaped chamber provided at its smaller end with an inlet and at its larger end with an outlet, a coneshaped screw mounted to rotate in said pump chamber, an inlet suction chamber at the smaller end of the pump chamber an inlet branch to said suction chamber which rises above the highest part of the pump chamber,'a discharge chamber at the larger end of the pump chamber having a delivery outlet, a pipe connecting the highest part of the suction chamber with the highest point in the inlet branch, and a pipe connecting the discharge chamber below the level of the water in same when the pump is stopped and vided at its smaller end-with an inlet and at its larger end with an outlet, a cone-shaped screw rotor rotating in said chamber, a suction chamber at the smaller end of the pump chamber, an inlet branch to said suction chamber, a discharge chamber at the larger end of the pumpchamber, a delivery plpe from said discharge chamber, a pipe connecting the suction chamber at its highest point with the inlet branch at a level above the suction chamber, a pipe connecting the lower part of the discharge chamber with the inlet branch contiguous to the suction chamber, and means for controlling the low thrugh said ipe. l

3. The com ination in a rotary pump of the screw type, of a cone-shaped chamber provided at its smaller end with an inlet and at its larger end with an outlet, a coneshaped screw rotor rotating in said chamber, a suction chamber at the smaller end of the pump chamber, an inlet branch to said suction chamber, a `discharge chamber at the larger end of the pump chamber, a delivery y pipe from said discharge chamber, a plipe connecting the suction chamber at its hig est point with the inlet branch at a level above the suction chamber, a pipe connecting the lower part of the discharge chamber with the inlet vbranch adjacent to the suction chamber, a cock in said pipe, and a water connection between the bearin s of the shaft and the discharge chamber o the pump. EDWARD BERRY TAll'l". 

